Compressor or vacuum pump provided with a transmission

Abstract

A compressor provided with a compressor element with a driven shaft, a motor with a drive shaft to drive the compressor element, and a transmission between the drive shaft and the driven shaft. The transmission includes a housing and at least a driven gearwheel that is mounted on the driven shaft and a drive gearwheel that is mounted on a drive shaft. The housing includes two separated chambers, a first chamber that is connected to the driven shaft and a second chamber which is separate from the first chamber. The first chamber is connected via a channel with the second chamber, whereby around the drive gearwheel or driven gearwheel, the second chamber is formed. The form of the second chamber is such that when the gearwheel in question rotates, a gas flow is created around this gearwheel which causes a negative pressure in the channel by the venturi effect.

The invention claimed is: 
     
       1. A compressor comprising with a compressor element with a driven shaft and a motor with a drive shaft to drive the compressor element, said compressor further being provided with a transmission between said drive shaft and said driven shaft, which the transmission comprising a housing and at least a driven gearwheel that is mounted on the driven shaft and a drive gearwheel that is mounted on the drive shaft, wherein the housing comprises two separated chambers, a first chamber that is connected to the driven shaft and a second chamber which is separate from the first chamber, whereby the first chamber is connected via a channel with the second chamber, whereby around the drive gearwheel or driven gearwheel the second chamber is formed, whereby the form of the second chamber is such that when the gearwheel in question rotates a gas flow is created around this gearwheel which causes a negative pressure in the channel by a venturi effect;
 wherein a distance in a radial direction between a wall of the second chamber and the gearwheel in question gets bigger in a rotation direction of the gearwheel in question. 
 
     
     
       2. The compressor according to  claim 1 , wherein the second chamber is integrated in a wall of the housing. 
     
     
       3. The compressor according to  claim 1 , wherein the second chamber extends along the gearwheel with a greatest diameter and/or a greatest peripheral speed. 
     
     
       4. The compressor according to  claim 1 , wherein the second chamber extends from 0° to 225° of a circumference of the gearwheel in question starting from a position of engagement of the gearwheels. 
     
     
       5. The compressor according to  claim 1 , wherein an opening of the second chamber is 25% to 75% of a circumference of the gearwheel in question. 
     
     
       6. The compressor according to  claim 5 , wherein the opening of the second chamber is 45% to 55% of the circumference of the gearwheel in question. 
     
     
       7. The compressor according to  claim 6 , wherein the opening of the second chamber is 50% of the circumference of the gearwheel in question. 
     
     
       8. The compressor according to  claim 1 , wherein said channel connects to an end of the second chamber, as seen in a rotation direction of the gearwheel in question. 
     
     
       9. The compressor according to  claim 1 , wherein said second chamber is in connection with a filter element or the like connected to the transmission. 
     
     
       10. A vacuum pump comprising with a vacuum pump element with a driven shaft and a motor with a drive shaft to drive the vacuum pump element, said vacuum pump further being provided with a transmission between said drive shaft and said driven shaft, wherein said transmission comprises a housing and at least a driven gearwheel that is mounted on the driven shaft and a drive gearwheel that is mounted on the drive shaft, and wherein the housing comprises two separated chambers, a first chamber that is connected to the driven shaft and a second chamber which is separate from the first chamber, whereby the first chamber is connected via a channel with the second chamber, whereby around the drive gearwheel or driven gearwheel the second chamber is formed, whereby the form of the second chamber is such that when the gearwheel in question rotates a gas flow is created around this gearwheel which causes a negative pressure in the channel by a venturi effect;
 wherein a distance in a radial direction between a wall of the second chamber and the gearwheel in question gets bigger in a rotation direction of the gearwheel in question.